The conversion PRESIMP_CONV applies various routine simplifications to
Boolean terms involving constants, e.g. p /\ T <=> p. It also tries to push
universal quantifiers through conjunctions and existential quantifiers through
disjunctions, e.g. (?x. p[x] \/ q[x]) <=> (?x. p[x]) \/ (?x. q[x])
(``miniscoping'') but does not transform away other connectives like
implication that would allow it do do this more completely.